Conventional cable and satellite television transmission is evolving into interactive television or televideo (IT) systems. IT systems combine the video broadcast capability characteristic of conventional broadcast television with computer-executed applications or programming responsive to input from viewers. By some estimates, IT systems under development could include the equivalent of 500 channels of programming, including video broadcasting and applications.
Meaningful access to large amounts of interactive television programming will require that viewers be able to obtain and comprehend vast amounts of programming and scheduling information. Conventional printed programming guides, such as T.V. Guide magazine or local newspapers, already provide only incomplete programming information for cable television networks with as few as 50 channels. It is expected that complete printed programming guides for the large amounts of programming in IT systems would be very large and expensive and unacceptably cumbersome.
Some conventional cable television networks dedicate a channel to a programming guide service, such as the Prevue Channel, Prevue Express, and Prevue Express Plus services provided by Prevue Networks, Inc. This conventional type of programming service lists the titles of programs scheduled for selected times. Typically, the titles of programs scheduled for about four television channels over a period of about two hours are listed simultaneously.
The service automatically scrolls through all or most of the channels available on the cable television network and automatically shifts the two-hour scheduling period shown according to the actual time. The same program schedule is delivered to all viewers on the cable television network. Viewers passively view the program schedule as it is scrolled.
In some systems, only about 60% of a viewer's television screen is used to show the program schedule. The remaining screen portion is used as an advertising window dedicated to broadcasting selected advertising or service identifications. One service that is frequently advertised in the advertising window of a programming guide is pay-per-view (PPV) television. Advertisements for PPV services often include video clips or segments relating to programs (e.g., motion pictures) available from the service.
The video content of the advertising window is the same for all viewers and is independent of the program schedule information that is shown simultaneously. The video content of the advertising window and the program schedule may even be generated from independent media or sources and mixed for broadcast on the dedicated programming guide channel.
At least one available system provides viewers with limited supplemental text descriptions regarding programming listed on a television program schedule. The system requires the viewer to have special decoder equipment to intercept and decode television program schedule information that is transmitted automatically during the vertical blanking interval of a conventional television signal.
Only a limited amount of television program schedule information may be encoded and broadcast during each vertical blanking interval. Many automatic transmissions of this type are required to deliver all the program schedule information and supplemental text descriptions to the decoder equipment, where the decoded information is stored. The program schedule information and supplemental text descriptions can be displayed and viewed on demand after being loaded into the decoder equipment.
Transmitting the program information only automatically during the vertical blanking signal of a conventional television signal requires that the many fragments of program information be assembled over time in the viewer's decoder equipment. As a consequence, this system is limited to providing only brief text descriptions of programs and improves only slightly upon conventional program listings. Moreover, the supplemental text descriptions provided by this system obscure much of the program schedule information and therefore requires that the viewer switch between viewing the program schedule information and the supplemental text descriptions.
Conventional cable television program guide services provide only the title or brief test descriptions of the scheduled programming. Such extremely limited information typically requires supplementation by a printed video guide for a viewer to obtain meaningful program schedule information. In view of the expected shortcomings of printed schedule guides for IT systems and the limited information provided by conventional cable television program guides, IT systems will require improved methods of providing program information to viewers.